/*
 * Copyright 2013 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.gradle.api.internal.artifacts.ivyservice.resolveengine.result;

import com.google.common.collect.Lists;
import org.gradle.api.artifacts.VersionConstraint;
import org.gradle.api.artifacts.component.BuildIdentifier;
import org.gradle.api.artifacts.component.ComponentSelector;
import org.gradle.api.artifacts.component.LibraryComponentSelector;
import org.gradle.api.artifacts.component.ModuleComponentSelector;
import org.gradle.api.attributes.AttributeContainer;
import org.gradle.api.internal.artifacts.ImmutableVersionConstraint;
import org.gradle.api.internal.artifacts.dependencies.DefaultImmutableVersionConstraint;
import org.gradle.api.internal.attributes.ImmutableAttributes;
import org.gradle.internal.component.external.model.DefaultModuleComponentSelector;
import org.gradle.internal.component.local.model.DefaultLibraryComponentSelector;
import org.gradle.internal.component.local.model.DefaultProjectComponentSelector;
import org.gradle.internal.serialize.AbstractSerializer;
import org.gradle.internal.serialize.Decoder;
import org.gradle.internal.serialize.Encoder;
import org.gradle.util.Path;

import java.io.IOException;
import java.util.List;

public class ComponentSelectorSerializer extends AbstractSerializer<ComponentSelector> {
    private final AttributeContainerSerializer attributeContainerSerializer;
    private final BuildIdentifierSerializer buildIdentifierSerializer;

    public ComponentSelectorSerializer(AttributeContainerSerializer attributeContainerSerializer) {
        this.attributeContainerSerializer = attributeContainerSerializer;
        this.buildIdentifierSerializer = new BuildIdentifierSerializer();
    }

    public ComponentSelector read(Decoder decoder) throws IOException {
        byte id = decoder.readByte();

        if (Implementation.ROOT_PROJECT.getId() == id) {
            BuildIdentifier buildIdentifier = buildIdentifierSerializer.read(decoder);
            String projectName = decoder.readString();
            return new DefaultProjectComponentSelector(buildIdentifier, Path.ROOT, Path.ROOT, projectName, readAttributes(decoder));
        } else if (Implementation.ROOT_BUILD_PROJECT.getId() == id) {
            BuildIdentifier buildIdentifier = buildIdentifierSerializer.read(decoder);
            Path projectPath = Path.path(decoder.readString());
            return new DefaultProjectComponentSelector(buildIdentifier, projectPath, projectPath, projectPath.getName(), readAttributes(decoder));
        } else if (Implementation.OTHER_BUILD_ROOT_PROJECT.getId() == id) {
            BuildIdentifier buildIdentifier = buildIdentifierSerializer.read(decoder);
            Path identityPath = Path.path(decoder.readString());
            return new DefaultProjectComponentSelector(buildIdentifier, identityPath, Path.ROOT, identityPath.getName(), readAttributes(decoder));
        } else if (Implementation.OTHER_BUILD_PROJECT.getId() == id) {
            BuildIdentifier buildIdentifier = buildIdentifierSerializer.read(decoder);
            Path identityPath = Path.path(decoder.readString());
            Path projectPath = Path.path(decoder.readString());
            return new DefaultProjectComponentSelector(buildIdentifier, identityPath, projectPath, projectPath.getName(), readAttributes(decoder));
        } else if (Implementation.MODULE.getId() == id) {
            return DefaultModuleComponentSelector.newSelector(decoder.readString(), decoder.readString(), readVersionConstraint(decoder), readAttributes(decoder));
        } else if (Implementation.LIBRARY.getId() == id) {
            return new DefaultLibraryComponentSelector(decoder.readString(), decoder.readNullableString(), decoder.readNullableString());
        }

        throw new IllegalArgumentException("Unable to find component selector with id: " + id);
    }

    private ImmutableAttributes readAttributes(Decoder decoder) throws IOException {
        return attributeContainerSerializer.read(decoder);
    }

    ImmutableVersionConstraint readVersionConstraint(Decoder decoder) throws IOException {
        String prefers = decoder.readString();
        int rejectCount = decoder.readSmallInt();
        List<String> rejects = Lists.newArrayListWithCapacity(rejectCount);
        for (int i = 0; i < rejectCount; i++) {
            rejects.add(decoder.readString());
        }
        return new DefaultImmutableVersionConstraint(prefers, rejects);
    }

    public void write(Encoder encoder, ComponentSelector value) throws IOException {
        if (value == null) {
            throw new IllegalArgumentException("Provided component selector may not be null");
        }

        Implementation implementation = resolveImplementation(value);

        encoder.writeByte(implementation.getId());

        if (implementation == Implementation.MODULE) {
            ModuleComponentSelector moduleComponentSelector = (ModuleComponentSelector) value;
            encoder.writeString(moduleComponentSelector.getGroup());
            encoder.writeString(moduleComponentSelector.getModule());
            VersionConstraint versionConstraint = moduleComponentSelector.getVersionConstraint();
            writeVersionConstraint(encoder, versionConstraint);
            writeAttributes(encoder, moduleComponentSelector.getAttributes());
        } else if (implementation == Implementation.ROOT_PROJECT) {
            DefaultProjectComponentSelector projectComponentSelector = (DefaultProjectComponentSelector) value;
            buildIdentifierSerializer.write(encoder, projectComponentSelector.getBuildIdentifier());
            encoder.writeString(projectComponentSelector.getProjectName());
            writeAttributes(encoder, projectComponentSelector.getAttributes());
        } else if (implementation == Implementation.ROOT_BUILD_PROJECT) {
            DefaultProjectComponentSelector projectComponentSelector = (DefaultProjectComponentSelector) value;
            buildIdentifierSerializer.write(encoder, projectComponentSelector.getBuildIdentifier());
            encoder.writeString(projectComponentSelector.getProjectPath());
            writeAttributes(encoder, projectComponentSelector.getAttributes());
        } else if (implementation == Implementation.OTHER_BUILD_ROOT_PROJECT) {
            DefaultProjectComponentSelector projectComponentSelector = (DefaultProjectComponentSelector) value;
            buildIdentifierSerializer.write(encoder, projectComponentSelector.getBuildIdentifier());
            encoder.writeString(projectComponentSelector.getIdentityPath().getPath());
            writeAttributes(encoder, projectComponentSelector.getAttributes());
        } else if (implementation == Implementation.OTHER_BUILD_PROJECT) {
            DefaultProjectComponentSelector projectComponentSelector = (DefaultProjectComponentSelector) value;
            buildIdentifierSerializer.write(encoder, projectComponentSelector.getBuildIdentifier());
            encoder.writeString(projectComponentSelector.getIdentityPath().getPath());
            encoder.writeString(projectComponentSelector.getProjectPath());
            writeAttributes(encoder, projectComponentSelector.getAttributes());
        } else if (implementation == Implementation.LIBRARY) {
            LibraryComponentSelector libraryComponentSelector = (LibraryComponentSelector) value;
            encoder.writeString(libraryComponentSelector.getProjectPath());
            encoder.writeNullableString(libraryComponentSelector.getLibraryName());
            encoder.writeNullableString(libraryComponentSelector.getVariant());
        } else {
            throw new IllegalStateException("Unsupported implementation type: " + implementation);
        }
    }

    private void writeAttributes(Encoder encoder, AttributeContainer attributes) throws IOException {
        attributeContainerSerializer.write(encoder, attributes);
    }

    private void writeVersionConstraint(Encoder encoder, VersionConstraint versionConstraint) throws IOException {
        encoder.writeString(versionConstraint.getPreferredVersion());
        List<String> rejectedVersions = versionConstraint.getRejectedVersions();
        encoder.writeSmallInt(rejectedVersions.size());
        for (String rejectedVersion : rejectedVersions) {
            encoder.writeString(rejectedVersion);
        }
    }

    private ComponentSelectorSerializer.Implementation resolveImplementation(ComponentSelector value) {
        Implementation implementation;

        if (value instanceof DefaultModuleComponentSelector) {
            implementation = Implementation.MODULE;
        } else if (value instanceof DefaultProjectComponentSelector) {
            DefaultProjectComponentSelector projectComponentSelector = (DefaultProjectComponentSelector) value;
            // Special case some common combinations of names and paths
            boolean isARootProject = projectComponentSelector.projectPath().equals(Path.ROOT);
            if (projectComponentSelector.getIdentityPath().equals(Path.ROOT) && isARootProject) {
                return Implementation.ROOT_PROJECT;
            }
            if (projectComponentSelector.getIdentityPath().equals(projectComponentSelector.projectPath()) && projectComponentSelector.projectPath().getName().equals(projectComponentSelector.getProjectName())) {
                return Implementation.ROOT_BUILD_PROJECT;
            }
            if (isARootProject && projectComponentSelector.getProjectName().equals(projectComponentSelector.getIdentityPath().getName())) {
                return Implementation.OTHER_BUILD_ROOT_PROJECT;
            }
            return Implementation.OTHER_BUILD_PROJECT;
        } else if (value instanceof DefaultLibraryComponentSelector) {
            implementation = Implementation.LIBRARY;
        } else {
            throw new IllegalArgumentException("Unsupported component selector class: " + value.getClass());
        }

        return implementation;
    }

    private enum Implementation {
        MODULE(1), ROOT_PROJECT(2), ROOT_BUILD_PROJECT(3), OTHER_BUILD_ROOT_PROJECT(4), OTHER_BUILD_PROJECT(5), LIBRARY(6), SNAPSHOT(7);

        private final byte id;

        Implementation(int id) {
            this.id = (byte) id;
        }

        byte getId() {
            return id;
        }
    }
}
